Karina Pallagst, director of the Shrinking Cities in a Global Perspective programme at the University of California, Berkeley, said there was "both a cultural and political taboo" about admitting decline in America.

Dozens of US cities may have entire neighbourhoods bulldozed as part of drastic "shrink to survive" proposals being considered by the Obama administration to tackle economic decline.

"In Detroit, shattered by the woes of the US car industry, there are already plans to split it into a collection of small urban centres separated from each other by countryside. 'The real question is not whether these cities shrink – we're all shrinking – but whether we let it happen in a destructive or sustainable way. Decline is a fact of life in Flint. Resisting it is like resisting gravity.'"

"The government looking at expanding a pioneering scheme in Flint, one of the poorest US cities, which involves razing entire districts and returning the land to nature. Local politicians believe the city must contract by as much as 40 per cent, concentrating the dwindling population and local services into a more viable area."